This part is a kind of semiconductor called 1SS401.

Function of this product has Schottoky DIODES.

Manufacturers : Jin Yu Semiconductor

Image and pinout :

Some of the text within the PDF file :

Schottoky DIODES FEATURES Low forward voltage : VF=0.38V(typ.) Low reverse current : IR=50uA(max) Small total capacitance : CT =46pF(typ.) 1SS4 01 SOT-323 1.ANODE 2. NC 3. CATHODE MARKING: Maximum Ratings @TA=25℃ Parameter Non-Repetitive Peak reverse voltage Peak Repetitive Peak reverse voltage Working Peak Reverse Voltage DC Blocking Voltage Forward Continuous Current Average Rectified Output Current Power Dissipation Junction temperature Storage temperature range Symbol VRM VRRM VRWM VR IFM IO Pd TJ TSTG Limits 25 20 700 300 100 125 -55-125 Electrical Characteristics @TA=25℃ Parameter Reverse Breakdown Voltage Forward voltage Reverse current Capacitance between terminals Symbol V (BR)R VF1 VF2 VF3 IR CT Min. 20 Typ. 0.16 0.22 0.38 46 Max. 0.45 50 Unit V V V V uA pF JinY [ ... ]

1SS401 PDF Datasheet Download